Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: Do we have enough data to support this?

Table 3 Clinical characteristics of representative studies on endoscopic resection for undifferentiated type early gastric cancer

Study	Year	Country	No. of patients with UD-EGC	No. of patients with PD/SRC	Age (yr)1	Sex (male)	SM invasion	Ulcer	Size (mm)1	Size > 20 mm
Kim et al[80]	2013	South Korea	74	55/19	61.8 ± 12.0	40 (54.1)	16 (21.6)	11 (14.9)	19.9 ± 12.5	36 (48.6)
Abe et al[87]	2013	Japan	97	18/77/22	62.0 (35.0-88.0)3	55 (56.7)	19 (19.6)	9 (9.3)	12.03	14 (14.4)
Park et al[88]	2012	South Korea	77	47/154	60.9 (33.0-82.0)	49 (63.6)	12 (15.6)	4 (5.2)	23.3 ± 14.0	35 (45.5)
Okada et al[89]	2012	Japan	1035	12/91	59.0 (34.0-91.0)	48 (46.6)	10 (9.7)	1 (1.0)	8.0 (1.0-33.0)3	NA
Kamada et al[76]	2012	Japan	46	NA	65.5 (29.0-90.0)	24 (52.2)	7 (15.2)	1 (2.2)	NA	8 (17.4)
Yamamoto et al[90]	2010	Japan	58	48/10	64.0 (33.0-81.0)	31 (53.4)	7 (12.1)	2 (3.4)	11.0 (2.0-28.0)	5 (8.6)
Kang et al[73]	2010	South Korea	60	30/30	56.7 ± 10.4	31 (51.7)	17 (28.3)	17 (28.3)	26.3 ± 12.9	31 (51.7)
Kim et al[74]	2009	South Korea	58	17/41	55.0 (26.0-81.0)	26 (44.8)	NA	0 (0)	13.3 ± 6.5	4 (6.9)

Data are expressed as absolute numbers (percentage) or mean ± SD.

¹Data are expressed as mean with standard deviation or range;

²Two patients had EGCs with histology of moderately to poorly differentiated adenocarcinoma;

³Data are expressed as median with or without range;

⁴Fifteen patients had EGCs with mixed type histology;

⁵A total of 103 EGCs in 101 patients were enrolled. UD-EGC: Undifferentiated typr early gastric cancer; PD: Poorly-differentiated adenocarcinoma; SRC: Signet-ring cell carcinoma; SM: Submucosa; NA: Not available.